


def fib(key):
    n,a,b = 0,1,2
    while n < key:
        yield b
        a,b = b,a+b
        n = n+1
    return "over"


print(fib(10))


f = fib(10)
print(next(f))
print(next(f))
print(next(f))
print(next(f))



